Lens and light emitting apparatus having the same

ABSTRACT

Provided is a lens. The lens may include a lens body having a convex top surface having a first recessed part at a central portion thereof and a flat surface at a circumference thereof and a flat bottom surface having a second recessed part at a central portion thereof, and a plurality of lens supports on the bottom surface of the lens body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of Ser. No. 12/875,671filed on Sep. 3, 2010, and claims priority under 35 U.S.C. §119 ofKorean Patent Application No. 10-2009-0112279 (filed on Nov. 19, 2009),which are hereby incorporated by reference in their entirety.

BACKGROUND

The present disclosure relates to a lens and a light emitting apparatusincluding the lens.

Light emitting devices such as light emitting diodes have advantages oflow power consumption, a long usable life cycle, and environmentalfriendly. Thus, the light emitting devices are being used for variouslight emitting apparatuses such as backlight units for electronicequipment, electronic displays, and lighting equipment.

In such a light emitting apparatus, a sealing resin layer is formed invarious lens shapes to surround a light emitting device, thereby toadjust a distribution characteristic of light emitted from the lightemitting device.

SUMMARY

Embodiments provide a light emitting apparatus having a novel structure.

Embodiments also provide a light emitting apparatus including a lenshaving a novel structure.

Embodiments also provide a light emitting apparatus having a superiorlight emitting characteristic in a lateral direction.

In one embodiment, a light emitting apparatus comprises: a substrate; alight emitting device package on the substrate; and a lens supported bythe substrate, the lens being disposed on the light emitting devicepackage, wherein the lens comprises a lens body comprising a firstrecessed part at a central portion of a top surface thereof and a secondrecessed part at a central portion of a bottom surface thereof and alens support disposed on the bottom surface of the lens body to supportthe lens body such that the bottom surface of the lens body is spacedfrom the substrate.

In another embodiment, a lens comprises: a lens body having a convex topsurface comprising a first recessed part at a central portion thereofand a flat surface at a circumference thereof and a flat bottom surfacecomprising a second recessed part at a central portion thereof; and aplurality of lens supports on the bottom surface of the lens body,wherein a ratio of a maximum depth of the first recessed part to amaximum thickness of the lens body ranges from about 0.06 to about 0.1,a ratio of a maximum depth of the second recessed part to a maximumthickness of the lens body ranges from about 0.5 to 0.75, and a ratio ofa maximum depth of the second recessed part to a maximum depth of thefirst recessed part ranges from about 6.25 to about 10, and a ratio of amaximum width of the first recessed part to a maximum width of the lensbody ranges from about 0.18 to about 0.3, a ratio of a maximum width ofthe second recessed part to a maximum width of the lens body ranges fromabout 0.14 to about 0.25, and a ratio of a maximum width of the secondrecessed part to a maximum width of the first recessed part ranges fromabout 0.7 to about 0.94.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are sectional views of a light emitting apparatusaccording to a first embodiment.

FIG. 3 is a sectional view of a light emitting apparatus according to asecond embodiment.

FIG. 4 is a sectional view of a light emitting device package in a lightemitting apparatus according to a third embodiment.

FIG. 5 is a sectional view of a light emitting device package in a lightemitting apparatus according to a fourth embodiment.

FIG. 6 is a sectional view of a light emitting device package in a lightemitting apparatus according to a fifth embodiment.

FIG. 7 is a sectional view of a light emitting device package in a lightemitting apparatus according to a sixth embodiment.

FIG. 8 is a sectional view of a light emitting device package in a lightemitting apparatus according to a seventh embodiment.

FIGS. 9 and 10 are views illustrating a light distributioncharacteristic of the light emitting apparatus according to the firstembodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the description of embodiments, it will be understood that when alayer (or film), region, pattern or structure is referred to as being‘on’ another layer (or film), region, pad or pattern, the terminology of‘on’ and ‘under’ includes both the meanings of ‘directly’ and‘indirectly’.

In the drawings, the thickness or size of each layer is exaggerated,omitted, or schematically illustrated for convenience in description andclarity. Also, the size of each element does not entirely reflect anactual size.

FIGS. 1 and 2 are sectional views of a light emitting apparatusaccording to a first embodiment.

Referring to FIGS. 1 and 2, a light emitting apparatus according to afirst embodiment includes a substrate 10, a light emitting devicepackage 20 disposed on the substrate 10, and a lens 30 disposed andsupported on the substrate 10 and disposed on the light emitting devicepackage 20.

The substrate 10 may be a printed circuit board (PCB). A circuit pattern(not shown) is disposed on the substrate 10, and the circuit pattern andthe light emitting device package 20 are electrically connected to eachother. Also, the substrate 10 may be a metal core printed circuit board(MCPCB).

The light emitting device package 20 includes a package body 21, atleast one light emitting device 22 disposed on the package body 21, aphosphor layer 23 surrounding the light emitting device 22, and asealing resin layer 24 surrounding the phosphor layer 23 on the packagebody 21.

Electrode layers (not shown) are disposed on the package body 21. Theelectrode layers pass through the package body 21 or disposed on asurface of the package body 21 to electrically connect the lightemitting device 22 to the circuit pattern of the substrate 10. Thepackage body 21 may be formed of various materials. For example, thepackage body 21 may be formed of one of a ceramic material, a resinmaterial, and a silicon material.

The light emitting device 22 may include a light emitting diode. Thelight emitting device 22 may be provided in plurality on the packagebody 21. In this embodiment, three light emitting devices 22 areprovided. The plurality of light emitting devices 22 may be connected toeach other in parallel or series. Also, the plurality of light emittingdevices 22 may be electrically connected to the electrode layers using aflip-chip method or a wire bonding method.

A light emitting diode emitting at least one of red light, green light,and blue light may be used as the light emitting device 22. In thisembodiment, the light emitting diode emitting the blue light isillustrated as an example.

The phosphor layer 23 may surround the light emitting device 22 on thepackage body 21. For example, the phosphor layer 23 may contain a yellowphosphor. The phosphor layer 23 may have a flat top surface and aconstant height on the package body 21.

The sealing resin layer 24 is disposed on the package body 21 tosurround the phosphor layer 23. The sealing resin layer 24 may be formedof a transparent resin material, for example, an epoxy resin or asilicon resin.

The sealing resin layer 24 may protrude from a central portion of a topsurface thereof. Also, the sealing resin layer 24 may be flat at acircumference of the top surface.

Although the phosphor layer 23 and the sealing resin layer 24 areseparated from each other in this embodiment, the present disclosure isnot limited thereto. For example, a phosphor may be dispersed into thesealing resin layer 24 on the whole without separating the phosphorlayer 23 from the sealing resin layer 24.

The lens 30 includes a lens body 31 and a lens support 34 supporting thelens body 31. The lens body 31 and the lens support 34 may be integratedwith each other using an injection molding. Alternatively, the lens body31 and the lens support 34 may be provided as separate parts, and thencoupled to each other using an adhesive.

The lens body 31 may have an approximately circular shape in plan view.A concave-convex part or roughness may be disposed on a bottom surfaceof the lens body 31. The concave-convex part or roughness may bedisposed on the bottom surface of the lens body 31 except for a portionwhere a second recessed part 33 is formed.

The lens support 34 may be provided in plurality on the bottom surfaceof the lens body 31. Although only two lens supports 34 are illustratedin this embodiment, the present disclosure is not limited thereto. Forexample, three or more lens supports 34 may be disposed spaced from eachother to stably support the lens body 31. A configuration or number ofthe lens support 34 may be variously modified according to its design.

The lens support 34 may have a gap between the lens body 31 and thesubstrate 10. Thus, air may flow through the gap to easily release heatgenerated in the light emitting device.

The lens support 34 may be supported by a top surface of the substrate10. A bottom surface of the lens support 34 may contact only the topsurface of the substrate 10.

Although only one lens 30 is disposed on the substrate 10 in thisembodiment, a plurality of lenses may be disposed on the substrate 10.

The lens body 31 may be formed of a transparent resin material. Also,the lens body 31 may be spaced a predetermined distance from thesubstrate 10 by the lens support 34. The lens support 34 may be firmlyattached to the substrate 10 using an adhesive.

The lens body 31 has a protruding top surface on the whole. A downwardlyconcave first recessed part 32 is disposed at a central portion of thetop surface of the lens body 31. Also, the lens body 31 has a flatbottom surface. An upward concave second recessed part 33 is disposed ata central portion of the bottom surface of the lens body 31. The firstrecessed part 32 and the second recessed part 33 vertically overlap eachother.

Since the first recessed part 32 and the second recessed part 33 aredisposed at the central portion of the lens body 31, the lens body 31has a thin thickness at the central portion thereof. The lens body 31has a thickness which becomes gradually thicker from the central portiontoward an edge portion and then thinner again. Also, a circumference ofthe top surface of the lens body 31 may be flat, and a lateral surfaceadjacent to the bottom surface of the lens body 31 may be perpendicularto the bottom surface of the lens body 31.

The first recessed part 32 may have a maximum depth (a) of about 0.3 mmto about 0.4 mm. The second recessed part 33 may have a maximum depth(b) of about 2.5 mm to about 3 mm. Also, the first recessed part 32 mayhave a maximum width (c) of about 3.5 mm to about 4 mm. The secondrecessed part 33 may have a maximum width (d) of about 2.8 mm to about 3mm.

The lens support 34 may have a maximum thickness (e) of about 0.5 mm toabout 0.8 mm.

The lens body 31 may have a maximum thickness (h) of about 4 mm to about5 mm. A maximum thickness (f) from the bottom surface of the lens body31 to the flat top surface may range from about 1.8 mm to about 2 mm. Athickness (g) from the flat top surface of the lens body 31 to a topsurface may range from about 2.2 mm to about 2.8 mm.

The lens body 31 may have a maximum width (j) of about 13 mm to about 19mm. The lens body may have a maximum width (i) of about 12 mm to about18 mm at a portion in which the top surface of the lens body 31 iscurved.

In the light emitting device package 20, the package body 21 may have amaximum thickness of about 0.3 mm to about 0.4 mm, and a maximum heightfrom the top surface of the package body 21 to a top surface of thesealing resin layer 24 may range from about 1.1 mm to about 1.5 mm.

In this embodiment, a ratio (a/h) of the maximum depth (a) of the firstrecessed part 32 to the maximum thickness (h) of the lens body 31 mayrange from about 0.06 to about 0.1. A ratio (b/h) of the maximum depth(b) of the second recessed part 33 to the maximum thickness (h) of thelens body 31 may range from about 0.5 to 0.75. A ratio (b/a) of themaximum depth (b) of the second recessed part 33 to the maximum depth(a) of the first recessed part 32 may range from about 6.25 to about 10.

A ratio (c/j) of the maximum width (c) of the first recessed part 32 tothe maximum width (j) of the lens body 31 may range from about 0.18 toabout 0.3. A ratio (d/j) of the maximum width (d) of the second recessedpart 33 to the maximum width (j) of the lens body 31 may range fromabout 0.14 to about 0.25. A ratio (d/c) of the maximum width (d) of thesecond recessed part 33 to the maximum width (c) of the first recessedpart 32 may range from about 0.7 to about 0.94.

At least portion of the sealing resin layer 24 is disposed within thesecond recessed part 33. The package body 21 has the maximum thicknessless than that of the lens support 34. The bottom surface of the lensbody 31 may be flush with the light emitting device 22 or the phosphorlayer 23 or flush with the sealing resin layer 24.

As above-described, the light emitting apparatus has superior lightemitting efficiency in a lateral direction. Light emitted from the lightemitting device 22 is reflected and refracted by the sealing resin layer24 and reflected and refracted by the second recessed part 33 to emit alarge amount of the light in the lateral direction. Specifically, thefirst recessed part 32 and the second recessed part 33 reduce an amountof light emitted in an upper direction.

FIGS. 9 and 10 are views illustrating a light distributioncharacteristic of the light emitting apparatus according to the firstembodiment.

Referring to FIGS. 9 and 10, the light emitting apparatus according tothe first embodiment emits a peak light at an angle of about 70° toabout 85° or about −70° to about −85° when an angle perpendicular to thesubstrate 10 is defined as 0°. That is, it may be seen that the lightemitted from the light emitting apparatus is mainly emitted in thelateral direction.

Hereinafter, light emitting apparatuses according to second to seventhembodiments have light distribution characteristics similar to that ofthe light emitting apparatus of FIGS. 9 and 10.

FIG. 3 is a sectional view of a light emitting apparatus according to asecond embodiment.

In descriptions of a light emitting apparatus according to a secondembodiment, descriptions that duplicate those for the light emittingapparatus according to the first embodiment will be omitted.

Referring to FIG. 3, in a light emitting apparatus according to a secondembodiment, a light emitting device package 20 includes a sealing resinlayer 24 contacting a substrate 10. The sealing resin layer 24 isdisposed on the substrate 10, a package body 21, and a phosphor layer23. Since the sealing resin layer 24 contacts the substrate 10 and alateral surface of the package body 21, a contact area therebetweenincreases. Thus, the sealing resin layer 24 may be firmly coupled.

FIG. 4 is a sectional view of a light emitting device package in a lightemitting apparatus according to a third embodiment.

In descriptions of a light emitting apparatus according to a thirdembodiment, descriptions that duplicate those for the light emittingapparatus according to the first embodiment will be omitted.

Referring to FIG. 4, in a light emitting apparatus according to a thirdembodiment, a light emitting device package 20 includes a package body21 and a phosphor layer 23 having a constant thickness on a lightemitting device 22. The phosphor layer 23 may have a curved shapeaccording to an arrangement of the light emitting device 22. That is,the phosphor layer 23 disposed on the package body 21 may have a heightless than that of the phosphor layer 23 disposed on the light emittingdevice 22. In the light emitting apparatus according to the thirdembodiment, since the phosphor layer 23 surrounds the light emittingdevice 22 at the constant thickness, a color variation of light emittedfrom the light emitting apparatus may be reduced.

FIG. 5 is a sectional view of a light emitting device package in a lightemitting apparatus according to a fourth embodiment.

In descriptions of a light emitting apparatus according to a fourthembodiment, descriptions that duplicate those for the light emittingapparatus according to the first embodiment will be omitted.

Referring to FIG. 5, in a light emitting apparatus according to a fourthembodiment, a light emitting device package 20 includes a package body21 and a phosphor layer 23 having a convex shape and disposed on a lightemitting device 22.

In the light emitting apparatus according to the fourth embodiment,since the phosphor layer 23 is formed using a dispensing method, itsmanufacturing process is simple.

FIG. 6 is a sectional view of a light emitting device package in a lightemitting apparatus according to a fifth embodiment.

In descriptions of a light emitting apparatus according to a fifthembodiment, descriptions that duplicate those for the light emittingapparatus according to the first embodiment will be omitted.

Referring to FIG. 6, in a light emitting apparatus according to a fifthembodiment, a light emitting device package 20 has a groove 21 a in atop surface of a package body 21. A sealing resin layer 24 is injectedinto the groove 21 a. Thus, a contact area between the sealing resinlayer 24 and the package body 21 increases to firmly couple the sealingresin layer 24 to the package body 21.

Although the groove 21 a is defined in the top surface of the packagebody 21 in FIG. 6, the groove 21 a may be defined in a lateral surfaceof the package body 21. Also, a protrusion instead of the groove 21 amay be disposed.

FIG. 7 is a sectional view of a light emitting device package in a lightemitting apparatus according to a sixth embodiment.

In descriptions of a light emitting apparatus according to a sixthembodiment, descriptions that duplicate those for the light emittingapparatus according to the first embodiment will be omitted.

Referring to FIG. 7, in a light emitting apparatus according to a sixthembodiment, a light emitting device package 20 has a double groove 21 bin a top surface of the a package body 21. A sealing resin layer 24 isinjected into the double groove 21 b. The double groove 21 b verticallyextends downward from the top surface of the package body 21, and an endof the double groove 21 b horizontally extends again. Thus, a contactarea between the sealing resin layer 24 and the package body 21increases. As a result, the sealing resin layer 24 within the doublegroove 21 b serves as a hook part, the sealing resin layer 24 may befirmly coupled to the package body 21.

FIG. 8 is a sectional view of a light emitting device package in a lightemitting apparatus according to a seventh embodiment.

In descriptions of a light emitting apparatus according to a seventhembodiment, descriptions that duplicate those for the light emittingapparatus according to the first embodiment will be omitted.

Referring to FIG. 8, a light emitting apparatus according to a seventhembodiment, a light emitting device package 20 includes a reflectionlayer 25 on a top surface of a package body 21. The reflection layer 25may be formed of a metal or an ink, which has a high reflectivity. Thereflection layer 25 may reduce an amount of light absorbed into thepackage body 21 to improve light emitting efficiency of the lightemitting apparatus.

As described above, the embodiments may provide the light emittingapparatus having a novel structure. Also, embodiments may provide thelight emitting apparatus including the lens having a novel structure.Also, embodiments may provide the light emitting apparatus having thesuperior light emitting characteristic in the lateral direction.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A lens, comprising: a lens body having a convex top surfacecomprising a first recessed part at a central portion thereof and a flatsurface at a circumference thereof and a flat bottom surface comprisinga second recessed part at a central portion thereof; and a plurality oflens supports on the bottom surface of the lens body, wherein a ratio ofa maximum depth of the first recessed part to a maximum thickness of thelens body ranges from about 0.06 to about 0.1, a ratio of a maximumdepth of the second recessed part to the maximum thickness of the lensbody ranges from about 0.5 to 0.75, and a ratio of the maximum depth ofthe second recessed part to the maximum depth of the first recessed partranges from about 6.25 to about 10, and a ratio of a maximum width ofthe first recessed part to a maximum width of the lens body ranges fromabout 0.18 to about 0.3, a ratio of a maximum width of the secondrecessed part to the maximum width of the lens body ranges from about0.14 to about 0.25, and a ratio of the maximum width of the secondrecessed part to the maximum width of the first recessed part rangesfrom about 0.7 to about 0.94.
 2. The lens according to claim 1, whereinthe first recessed part and the second recessed part vertically overlapeach other.
 3. The lens according to claim 1, wherein the plurality oflens supports are spaced apart from each other.
 4. The lens according toclaim 3, wherein the plurality of lens supports comprises at least threeor more lens supports.
 5. The lens according to claim 1, wherein aconcave-convex part or roughness is disposed on the bottom surface ofthe lens body except for a portion where the second recessed part isformed.